In recent years, with the requirement for saving resources, an image forming apparatus forming an image with erasable developer and an image erasing apparatus were introduced. This image erasing apparatus erases an image by applying heat or light to a recording medium on which the erasable developer is present to erase the developer. Accordingly, the erased recording medium can be reused.
Here, there is a problem regarding the treatment of a secret document when an image is formed on the secret document by the image forming apparatus. Recording mediums from which images are erased are accumulated once in a recording medium supply device such as a sheet feeding cassette. The image erasing apparatus is supplied with recording mediums from the recording medium supply device sheet by sheet and erases an image by heat.
When the images are erased from plural sheets of secret documents and the sheets are accumulated in the same recording medium supply device as typical documents, the secret documents may be read by a third party before an image erasing process is started.
When the erasing of the images is not complete and the sheets are discharged to an accumulation unit of non-reusable recording mediums in the same path as typical documents, the secret documents may be read by a third party.
From this point of view, a technique of surrounding a part accessible by a third party with a barrier wall having an openable door, providing the door with a key having a sensor, and erasing an image when all the sensors indicate that the door is locked is disclosed.